1. Field of the Invention
The present invention relates to a packaging arrangement for the containment of at least one hydrophilic contact lens in a sterile aqueous solution. More specifically, the invention pertains to a packaging arrangement wherein a plurality of disposable hydrophilic contact lenses are contained in a specific number of individual packaging arrangements adapted to be collectively and compactly housed in a box-like container or carton so as to provide a specified or essentially measured supply of contact lenses for use by a consumer over a predetermined and possibly lengthy period of time.
The packaging of hydrophilic contact lenses in a sterile aqueous solution is well known in the contact lens manufacturing technology. In particular, such packaging arrangements generally consist of so-called blister packages which are employed for the storage and dispensing of the hydrophilic contact lenses by a medical practitioner or to a consumer who intends to wear the contact lenses. Generally, such hydrophilic contact lenses, which may be disposable after a single wear or short-term use, are manufactured from suitable hydrophilic polymeric materials. These materials may be, amongst others, copolymers of hydroxyethyl methacrylate containing from about 20% to 90% or more of water, depending upon the polymer composition. Generally, such contact lenses must be stored in a sterile aqueous solution, usually in isotonic saline solution in order to prevent dehydration and to maintain the lenses in a ready-to-wear condition.
2. Discussion of the Prior Art
Heretofore, contact lens manufacturers normally utilized stoppered glass bottles containing sterile saline solutions in which the hydrophilic contact lenses were immersed as storage and shipping containers for individual contact lenses. Each bottle was sealed with a suitable silicone stopper and provided with a metal closure as a safety seal in the configuration of an overcap. When the contact lens was intended to be removed from the bottle for use by a patient, the metal closure safety seal was required to be initially torn off the bottle, thereafter the stopper withdrawn and the lens lifted out from the bottle through the intermediary of a suitable plastic tweezer or pouring the contents out. This entailed the implementation of an extremely complicated procedure, since the contact lens was difficult to grasp and remove from the saline solution contained in the bottle due to the transparent nature of the contact lens which rendered it practically invisible to the human eye.
More recently, containments in the form of blister packages have been developed for hydrophilic contact lenses, and which enable the storage and shipping of the hydrophilic contact lenses in a simple and inexpensive expedient manner, while concurrently facilitating the conveniently easy removal of the contact lens by a practitioner or a patient.
For instance, a blister package which is adapted to provide a sterile sealed storage environment for a disposable or single-use hydrophilic contact lens, wherein the lens is immersed in a sterile aqueous solution; for example, such as in an isotonic saline solution, is described in U.S. Pat. No. 4,691,820 to Martinez; which is assigned to the common assignee for the present invention, and the disclosure of which is incorporated herein by reference.
Thus, in the above-mentioned U.S. patent, the blister package for storing and dispensing a hydrophilic contact lens includes an injection-molded or thermoformed plastic base portion incorporating a molded cavity which is surrounded by an outstanding planar flange about the rim of the cavity. A flexible cover sheet is adhered to the surface of the flange so as to sealingly enclose the cavity in a generally liquid-tight mode. Within the cavity of the base portion, a hydrophilic contact lens is immersed in a sterile aqueous solution, such as an-isotonic saline solution. A portion of the side wall of the cavity is inclined to form a ramp extending upwardly towards the flange from the bottom of the cavity, and the cover sheet is adapted to be stripped from the flange in order to expose the cavity and inclined side wall whereupon the lens may be readily manually removed by being slid upwardly and out of the cavity along the inclined ramp surface of the cavity.
Although the foregoing blister package construction for the containment of contact lenses clearly provides a significant advance over prior structures requiring glass bottles and removable stopper arrangements for housing the contact lenses, the present invention further improves upon the uses and versatility of blister package construction in that the cavity is essentially of a semi-spherical configuration dimensioned so as to be adapted to closely support the contact lens therein immersed in an aqueous solution for ease of removal and also to facilitate an inspection process. Moreover, the foregoing construction primarily considers the utilization of such blister packages for the dispensing of individual contact lenses, with such blister packages being ordinarily separate or single packagings, which may then be housed in larger quantities in a further container, such as a rigid cardboard or paperboard carton of usual construction employed for the retail sales of the lenses.
Accordingly, it is an important aspect to be able to furnish a user of such disposable hydrophilic contact lenses with a specific supply of contact lenses, the latter of which are normally worn for only a single day; in essence, for ordinarily 8 to 18 hours within a 24-hour period and thereafter discarded. Hereby, the packaging of a supply of contact lenses should enable the user to store and provide indication for replenishing the supply of contact lenses at regular intervals; for example, at periods of 30 days, although pursuant to the invention, it is also possible to contemplate providing packages containing supplies of the contact lenses for shorter or considerably lengthier periods of days. Consequently, the present invention contemplates the provision of packaging arrangements for specified quantities of such hydrophilic contact lenses, wherein these packaging arrangements are boxed enabling a rapid and precise determination as to the quantity of hydrophilic contact lenses contained therein, and with the blister packages being shaped to enable large quantities to be stored in carton-like packaging arrangements of a compact nature which is completely protective of the hydrophilic lenses, while avoiding them being unwieldy in sizes and external dimensions.